/Engine/Plugins/Protocols/MQTT/Source/MQTTCore/Public/IMQTTClient.h
Connect using the clients URL. Set bCleanSession = false to resume previous session.
[TFuture](API\Runtime\Core\Async\TFuture)< [EMQTTConnectReturnCode](API\Plugins\MQTTCore\EMQTTConnectReturnCode) > Connect ( bool bCleanSession )